Electrically-operated switch.



I w. 0. LUM.

ELEGTBICALLY OPERATES SWITCH.

APPLICAHON FILED JUNE HI 1912.

Patented May 11, 1915.-

WITNESSES memo STATES PATENT carton WALTER o. LUM, or wrpxmsiznne, PENNSYLVANIA,'ASSIGNOR TO WESTINGHOUSE" ELECTRIC MANUFACTURING COMPANY, A CORPORATIQN OF PENNSYLVANIA.

EI JECTRIGALLY-OPERATED SWITCH.

To all whom it may concern; l

Be it known that I, WALTER 0. Lost, a citlzen of the United States, and a resident of Wilkinsburg, in the county of Allegheny and State of. Pennsylvania, have invented a new and useful. improvement in Electrically-Operated Switches, of which the following is a specification.

My invention relates to"'elcctromagnetically operated switches, and it has special reference to switches of this character which are adapted for use with systems of electric motor control.

()ne object of my inventionfis to provide r a switch of the class above indicated that shall be simple and durable in construction "and have the characteristics of operating only when the energy supplied to its actuating winding falls within predetermined limits j Anotherobject of my invention is to provide means for magnetically separating or insulating a pair, of substantially parallel magnetic paths from each other that shall not constitute a short-circqi'ted secondary Winding fol-the flux either path Independently operated switches are very largely used in the control of electric motors, andswitches have been previously utilized for this purpose having two paths for l the magnetflux, one of which predominates current supplied to the coil falls within predetermined limits. In order to' insure the provided with a short circuited coil or single to hold the-switch open when the energy supplied-to the actuating coil exceeds a predetermined value, and the other of which predominates to close the switch when the look-out action, when a .relativel y la rgev mm rent is first supplied 'to the coil, the portion of the magnetic circuit which is depended upon to close-the swltch has sometimes been turn of conducting material which tends to divert the flux into the other path.

According to my present invention, I utilize means for concentracting the leakage at a desired point in order to produce a maximum holding-out ctlect vduringthe saturation of the branch of the core member which is parallelv to the leakage path. At thesame time, I avoid short circuiting either path and, consequently, my invention is particularly well adapted for such switches as are called upon to operate on alternating cur Specification of Letters Patent. Pai-Qntgfl luay 11, 1915 Application filed June 14, 1912. Serial No. 703,761. i:

rent circuits and are known as alternating current switches.

accompanying drawings ing coil of the switch shown in Fig. 1-, and lilg. 3 1s a view, corresponding to Fi 2, of a modified structure which may be substi-" tuted for that of Fig; 2.

Referring to Figs. 1 and 2 ot the drawings, the structure here shown comprises a slab or base l of insulating material, a stationary magnetizable member 2 secured thereto, a movable armature 3, a stationary switch contact member l, a coiipcrating mow able contact member 5, and an actuating COll 6. The stationary core mcn'ibor 2 is substantially U-shaped and is provided'with a projection or lug 7 and a damper 8.

The movabli armature 3 is provided with a pro ection 9v which forms an obtuse angle with the body ot the armature and Is 15:0

vidcd with anadjusting screw 10; The a1'-' mature is pivotally mounted ona pin 11 i which is secured to a stationary bracket 12.

When the switch open, the projection 9 ot the armature 1S substantially parallel to an arm 13 of the stationary member .3 and the adjusting screw 10 engages the projecs tion 7. The damper 8 is secured to the arm 13 adjacent to the projection 9 of. the urinetn re and forces the leakageiflun, which traverses the projectionl to pass tl\l'OllXll the projection 7, Itjistherefore evident that the leakage flux exerts a maximum torcctending to hold the switch open.

per or some good conducting material and.

formed as shown in Fig. 2. \Vhen so formed, it obviously tends'to prevent the flux from passing through it. The damper may, however, constitute a-plate of some good conducting material, asshown in Fife 2 and, since the arm 13 is smaller in cross section, it will be saturated and the leakage flux which thou traverses the projection 9 will prevent the switch from being closed.

- Substantially the same result will be separatively Wide limits without tending to open the switch, by reason of the fact that the projection 9 is then widely separated from'the'arm 13. A

I desire that only such limitations shall be imposed as are indicated in the appended claims.

I claim'as my invention:

1. A magnet comprising a U-shaped stationary magnetizable member, an armature pivotally mounted near the outer end of one branch of the U-shapedmember and having a projection extending substantially parallel to said branch when the armature occupies one extreme position-and at an angle to said branch when the armature occupies its other extreme position, and means for magnetically' insulating the armature projection fror'nlt he' adjacent branch of the stationary member except at the free end of the projection. 7

2. A magnet comprising a U-shaped stationary magnetizable member, an armature pivotally mounted near the outer end of one branch of the Ueshaped member and having a projection extending substantially parallel to said branch-when the armature occupies one extreme position, and a damper of conducting material located at one side of the branch of the U-sliaped member that is adj acent to the armature projection.

3. A magnet comprising a U-shaped stationary magnetizable member, an armature pivotally mounted near the outer end of one branch of the U-shaped member and having a projection extending substantially parallel to said branch when the armature occupies one extreme position, and a damper comprising a closed loop of conducting material interposed betweenthe armature projection and the adjacent branch of the stationary magnetizable member and parallel to said branch.

4. An alternating current magnet switch comprising a-stationary magnetizalile member, a movable armature, a magnetizing coil,

the stationary member and the armature providing, when energized, two flux paths that tend to actuate the armature in opposite directions to respectively open and close the switch, and a damper comprising a closed turn of conductingmaterial located in a plane between, and substantially parallel to, the two paths.

5. An alternating current magnet switch comprising a U-shaped stationary magnetizable member, a stationary contact member, an armature pivotally mounted near the outer end of one branch of the U-shaped member and having a projection extending substantially parallel to said branch when the switch is open, a movable contact member carried by the armature, the stationary magnetizable member and the armature pro viding two flux paths that tend, respectively, to open and close the switch, and means for magnetically insulating the two paths from each other.

6. An alternating current magnet switch omprising a U-shapedv stationary magnetizable member, a stationary contact member, an armature pivotally mounted near the outer end of one branch of the U-shap'ed member and having a projection extending substantially parallel to said branch. when the switch is open, a movable contact member carried by the armature, the stationary magnetizable member and the armature providing two flux paths that tend, respectively, ","to open and close the switch, and a damper of conducting material for magnetically insulating the two paths from each other.

7. An alternating current magnet switch comprising a U-shaped stationary magnetiza-ble member, a stationary contact member, an armature pivotally i iuounted near the outer end 'of one branch of the U-shaped member and having a", projection extending substantially parallel to said branch when I the switch is open, a movable contact member carried by the armature, the stationary magnetizable member and the armature providing two flux paths that tend, respectively, to open and close the switch, and a damper comprising a closed turn of conducting material secured to the branch of the stationary magnetizable member adjacent to the armature projection.

In testimony whereof, I have hereunto subscribed my name this 27th day of May,

1912. WALTER 0; LUM.

Witnesses:

B. B. Hmns, M. Mnnz. 

